Substrate cleaning apparatus, substrate processing apparatus, and method of cleaning substrate

ABSTRACT

A substrate cleaning apparatus and related apparatuses/methods are disclosed. In one embodiment, a substrate cleaning apparatus includes: a first spindle group including a first driving spindle having a first driving roller configured to rotate a substrate and an idler spindle having a driven roller rotated by the substrate; a second spindle group including a plurality of second driving spindles each having a second driving roller configured to rotate the substrate; a cleaning mechanism configured to clean the substrate rotated by the first driving roller and the plurality of second driving rollers; and a rotation detector configured to detect the rotational speed of the driven roller. The driven roller is positioned on the opposite side to a direction in which the substrate receives a force from the cleaning mechanism.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a substrate cleaning apparatus, asubstrate processing apparatus, and a method of cleaning a substrate.

The present application claims priority based on Japanese PatentApplication No. 2017-097621 filed on May 16, 2017 in Japan, the contentsof which are incorporated herein by reference.

Description of Related Art

Conventionally, a substrate cleaning apparatus used in a substrateprocessing apparatus as disclosed in the following Japanese Patent No.4937807 is known. The substrate cleaning apparatus includes a substrateholding and rotating mechanism configured to rotate a substrate (forexample, a circular semiconductor substrate or a semiconductor wafer)while holding the substrate between a first spindle group and a secondspindle group, and a cleaning mechanism configured to clean thesubstrate. Each of the first spindle group and the second spindle grouphas two driving spindles configured to rotate the substrate. While thesubstrate is held and rotated by these four driving spindles, thesubstrate is cleaned by the cleaning mechanism.

In addition, in this type of substrate cleaning apparatus, in order tostabilize the quality of a cleaned substrate, that is, in order toprevent generation of concerns such as attachment of a particle on thecleaned substrate including not only the center of the substrate butalso a peripheral portion thereof, it is required to accurately measurethe rotational speed of the substrate. As a method of measuring therotational speed of a substrate, Japanese Unexamined Patent Application,First Publication No. 10-289889 discloses a method of bringing a drivenroller into contact with an outer periphery of a substrate andintegrally rotating the driven roller and a slit plate to detect therotation state of the slit plate.

By the way, miniaturization of a semiconductor substrate has progressedin recent years. Therefore, it has been required to remove even minutedeposits that were not a problem in the past from the substrate as muchas possible. Therefore, in order to eliminate concerns such asattachment of a particle after cleaning the substrate, a higher level ofmanagement of a substrate cleaning process at the time of cleaning isalso required.

For example, in a constitution in which the rotational speed ofasubstrate is indirectly detected by detecting the rotational speed of adriven roller as in the substrate cleaning apparatus disclosed in theabove Japanese Unexamined Patent Application, First Publication No.10-289889, it has been found that slip occurring between the drivenroller and the substrate reduces the detection accuracy of therotational speed of the substrate although this has not been a problemusually. Reduction in detection accuracy of the rotational speed of thesubstrate due to slip can be one of reasons causing non-uniform cleaningperformance. Therefore, in order to suppress occurrence of such slip,for example, it is effective to increase a pressing force of the drivenroller against the substrate.

Meanwhile, for example, in the substrate cleaning apparatus disclosed inJapanese Patent No. 4937807, as described above, a holding and rotatingunit 52 of each spindle 50 is brought into contact with a peripheralportion of a substrate W to hold the substrate W (refer to FIG. 9 ofJapanese Patent No. 4937807). In the case of the four driving rollers asdisclosed in Japanese Patent No. 4937807, when a holding force withwhich the holding and rotating unit holds the substrate W is notuniform, rotation of the substrate W held by the holding and rotatingunit is not stabilized, and processing efficiency of cleaning of thesubstrate W or the like may be lowered. In addition, in a case where adriven roller for measuring the rotational speed of the substrate isbrought into contact with the substrate with a strong pressing force, abalance of forces applied to the substrate is lost, and deformation ofthe substrate or the like may occur. Furthermore, if the number ofrollers in contact with the substrate is increased, dirt attached to therollers due to cleaning is attached again to the substrate, and thesubstrate may be contaminated easily.

For the above reasons, in a circumstance in which the cleaning levelrequired for a semiconductor substrate has been further increased inrecent years, in order to meet such a requirement, in a case ofcontinuously cleaning a plurality of substrates with a substratecleaning apparatus, it has become difficult to accurately measure therotational speed of a substrate in a substrate holding and rotatingmechanism while stabilizing the quality of cleaning of the substrateused for the substrate cleaning apparatus.

SUMMARY OF THE INVENTION

The present invention has been achieved in view of such circumstancesand provides a substrate cleaning apparatus, a substrate processingapparatus, and a method of cleaning a substrate capable of accuratelymeasuring the rotational speed of a substrate using a driven rollerwhile stabilizing the quality of cleaning of the substrate.

A first aspect of the present invention is a substrate cleaningapparatus including: a first spindle group including a first drivingspindle having a first driving roller configured to rotate a substrateand an idler spindle having a driven roller rotated by the substrate; asecond spindle group including a plurality of second driving spindleseach having a second driving roller configured to rotate the substrate;a cleaning mechanism configured to clean the substrate rotated by thefirst driving roller and the plurality of second driving rollers; and arotation detector configured to detect the rotational speed of thedriven roller, in which the driven roller is positioned on the oppositeside to a direction in which the substrate receives a force from thecleaning mechanism.

In the substrate cleaning apparatus according to the above aspect, thedriven roller is positioned on the opposite side to a direction in whichthe substrate receives a force from the cleaning mechanism. This makesit possible to effectively utilize a pressing force of the cleaningmechanism as a force for pressing the substrate against the drivingroller, for example, as compared with a case where the driven roller ispositioned in a direction in which the substrate receives a force fromthe cleaning mechanism. Therefore, even if one driving roller in theconstitution of Japanese Patent No. 4937807 is replaced with a drivenroller, each driving roller can reliably rotate the substrate.

In addition, the number of rollers in contact with the substrate isreduced, and occurrence of contamination of the substrate by dirtattached to these rollers can be suppressed, for example, as comparedwith a case where a driven roller is added to the constitution ofJapanese Patent No. 4937807.

Furthermore, even if the pressing force of the driven roller against thesubstrate is equal to the pressing force of the driving roller againstthe substrate, a balance of the forces applied to the substrate is notdeteriorated as compared with the constitution of Japanese Patent No.4937807. Therefore, it is possible to suppress slip occurring betweenthe driven roller and the substrate by pressing the driven rolleragainst the substrate with a strong force while suppressing deformationof the substrate or the like.

As described above, according to the substrate cleaning apparatusaccording to the above aspect, the rotation detector detects therotational speed of the driven roller and can thereby stabilize thequality of cleaning of the substrate while accurately measuring therotational speed of the substrate.

A second aspect of the present invention is the substrate cleaningapparatus according to the first aspect, in which a moment of inertiawhen the driven roller is rotated may be smaller than a moment ofinertia when the first driving roller is rotated.

In this case, by reducing the moment of inertia of the driven roller,the driven roller is easily rotated together with the substrate. Thatis, it is possible to suppress slip occurring between the driven rollerand the substrate. Therefore, detection accuracy of the rotational speedof the substrate by the rotation detector can be improved.

A third aspect of the present invention is the substrate cleaningapparatus according to the first or second aspect, in which thesubstrate cleaning apparatus may include: a first moving mechanismconfigured to hold the first spindle group so as to be slidable androtationally movable; and a second moving mechanism configured to holdthe second spindle group so as to be slidable and not to be rotationallymovable.

In this case, when the substrate is held between the first spindle groupand the second spindle group, the first spindle group rotationallymoves, and a balance of holding forces of the substrate by the spindlescan be thereby uniform.

A fourth aspect of the present invention is the substrate cleaningapparatus according to any one of the first to third aspects, in which asubstrate holding and rotating mechanism including the first spindlegroup and the second spindle group may be a mechanism in which thesubstrate is held vertically.

A fifth aspect of the present invention is the substrate cleaningapparatus according to any one of the first to fourth aspects includinga dog connected to the idler spindle and a sensor to generate an ON/OFFsignal output in response to a movement of the dog.

A sixth aspect of the present invention is a substrate processingapparatus including: the substrate cleaning apparatus according to anyone of the first to fifth aspects; and a polishing section for polishingthe substrate.

According to the substrate processing apparatus according to the aboveaspect, when a substrate polished by the polishing section is cleaned,it is possible to suppress, for example, attachment of dirt of a rollerto the substrate again and to stabilize the quality of the processedsubstrate while accurately measuring the rotational speed of thesubstrate.

A seventh aspect of the present invention is a method configured toclean a substrate with the substrate cleaning apparatus according to anyone of the first to fifth aspects, including: holding the substrate on asubstrate holding and rotating mechanism including the first spindlegroup and the second spindle group; rotating the substrate; cleaning thesubstrate with a cleaning member while injecting a cleaning liquid tothe substrate; stopping injection of the cleaning liquid; and separatingthe cleaning member from the substrate to stop rotation of thesubstrate.

According to the above aspects of the present invention, it is possibleto provide a substrate cleaning apparatus, a substrate processingapparatus, and a method of cleaning a substrate capable of accuratelymeasuring the rotational speed of a substrate using a driven rollerwhile stabilizing the quality of cleaning of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view showing the constitution of a substrateprocessing apparatus according to the present embodiment;

FIG. 2A is a plan view showing a cleaning section;

FIG. 2B is a side view showing the cleaning section;

FIG. 3 is a perspective view showing a substrate holding and rotatingmechanism included in a substrate cleaning apparatus in FIG. 1;

FIG. 4 is a cross-sectional view taken along line A-A of the substrateholding and rotating mechanism of FIG. 3;

FIG. 5 is a cross-sectional view taken along line B-B of the substrateholding and rotating mechanism of FIG. 3;

FIG. 6 is a plan view of a first moving mechanism in FIG. 3;

FIG. 7 is a perspective view showing a roll type cleaning mechanism;

FIG. 8 is a perspective view showing a pencil type cleaning mechanism;

FIG. 9A is a schematic view showing an operation of the substratecleaning apparatus;

FIG. 9B is a schematic view showing an operation of the substratecleaning apparatus;

FIG. 9C is a schematic view showing an operation of the substratecleaning apparatus;

FIG. 9D is a schematic view showing an operation of the substratecleaning apparatus; and

FIG. 10 is a flowchart showing a flow of cleaning a substrate.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the constitutions of a substrate cleaning apparatus and asubstrate processing apparatus according to the present embodiment willbe described in detail with reference to FIGS. 1 to 9. Incidentally, inthe drawings used in the following description, the scale isappropriately changed in order to make each part have a recognizablesize. In addition, in order to facilitate understanding of theconstitution of each part, illustration of each part may be partiallyomitted.

(Substrate Processing Apparatus)

First, an embodiment of the substrate processing apparatus will bedescribed. FIG. 1 is a plan view showing the overall constitution of thesubstrate processing apparatus according to the present embodiment. Asshown in FIG. 1, the substrate processing apparatus includes asubstantially rectangular housing 101, and the inside of the housing 101is partitioned into a load/unload section 102, a polishing section 103,and a cleaning section 104 by partition walls 101 a and 101 b. Theload/unload section 102, the polishing section 103, and the cleaningsection 104 are independently assembled and independently evacuated. Inaddition, the substrate processing apparatus includes a control section105 for controlling a substrate processing operation.

The load/unload section 102 includes two or more (four in the presentembodiment) front load units 120 on which a wafer cassette for storing alarge number of substrates (wafers) is placed. The front load units 120are disposed adjacent to the housing 101 and are arranged in a widthdirection (direction perpendicular to a longitudinal direction) of thesubstrate processing apparatus. An open cassette, a standardmanufacturing interface (SMIF) pod, or a front opening unified pod(FOUP) can be mounted on each of the front load units 120. Here, each ofthe SMIF and FOUP is an airtight container capable of maintaining anenvironment independent of an external space by housing a wafer cassettetherein and being covered with a partition wall.

In addition, a traveling mechanism 121 is disposed along the row of thefront load units 120 in the load/unload section 102, and two transportrobots (loaders) 122 movable in an arrangement direction of the wafercassette are disposed on the traveling mechanism 121. The transportrobots 122 can access the wafer cassette mounted on each of the frontload units 120 by moving on the traveling mechanism 121. Each of thetransport robots 122 has two hands at the top and the bottom, uses theupper hand when returning a processed substrate to the wafer cassette,and uses the lower hand when taking out an unprocessed substrate fromthe wafer cassette. Each of the transport robots 122 can use the upperand lower hands properly. Furthermore, the lower hand of the transportrobot 122 is rotated around an axis thereof to be able to place thesubstrate upside down.

The load/unload section 102 is a region where it is necessary to keepthe cleanest state. Therefore, the inside of the load/unload section 102is maintained all the times at a higher pressure than each of theoutside of the substrate processing apparatus, the polishing section103, and the cleaning section 104. The polishing section 103 is thedirtiest region because of using a slurry as a polishing liquid.Therefore, a negative pressure is formed inside the polishing section103, and the pressure thereof is maintained to be lower than theinternal pressure of the cleaning section 104. A filter fan unit (notshown) including a clean air filter such as a HEPA filter, an ULPAfilter, or a chemical filter is disposed in the load/unload section 102,and clean air from which a particle, a toxic vapor, and a poisonous gashave been removed blows out all the times from the filter fan unit.

The polishing section 103 is a region where a substrate is polished(planarization and chemical mechanical polishing) and includes a firstpolishing unit 103A, a second polishing unit 103B, a third polishingunit 103C, and a fourth polishing unit 103D. As shown in FIG. 1, thefirst polishing unit 103A, the second polishing unit 103B, the thirdpolishing unit 103C, and the fourth polishing unit 103D are arranged ina longitudinal direction of the substrate processing apparatus.

As shown in FIG. 1, the first polishing unit 103A includes: a polishingtable 130A to which a polishing pad 110 having a polishing surface isattached; a top ring 131A configured to hold a substrate and polishingthe substrate while pressing the substrate against the polishing pad 110on the polishing table 130A; a polishing liquid supply nozzle 132A forsupplying a polishing liquid or a dressing liquid (for example, purewater) to the polishing pad 110; a dresser 133A for dressing thepolishing surface of the polishing pad 110; and an atomizer 134A forinjecting a mixed fluid of a liquid (for example, pure water) and a gas(for example, a nitrogen gas) or a liquid (for example, pure water) in aform of mist to the polishing surface.

Similarly, the second polishing unit 103B includes a polishing table130B to which the polishing pad 110 is attached, a top ring 131B, apolishing liquid supply nozzle 132B, a dresser 133B, and an atomizer134B. The third polishing unit 103C includes a polishing table 130C towhich the polishing pad 110 is attached, a top ring 131C, a polishingliquid supply nozzle 132C, a dresser 133C, and an atomizer 134C. Thefourth polishing unit 1031) includes a polishing table 130D to which thepolishing pad 110 is attached, a top ring 131D, a polishing liquidsupply nozzle 132D, a dresser 133), and an atomizer 134D.

The first polishing unit 103A, the second polishing unit 103B, the thirdpolishing unit 103C, and the fourth polishing unit 103D have the sameconstitution as one another. Therefore, hereinafter, the first polishingunit 103A will be described as a representative.

Next, a transport mechanism for transporting a substrate will bedescribed. As shown in FIG. 1, a first linear transporter 106 isdisposed adjacent to the first polishing unit 103A and the secondpolishing unit 103B. The first linear transporter 106 is a mechanism fortransporting a substrate among four transport positions in a directionin which the polishing units 103A and 103B are arranged (referred to asa first transport position TP1, a second transport position TP2, a thirdtransport position TP3, and a fourth transport position TP4 in orderfrom the side of the load/unload section).

In addition, a second linear transporter 107 is disposed adjacent to thethird polishing unit 103C and the fourth polishing unit 103D. The secondlinear transporter 107 is a mechanism for transporting a substrate amongthree transport positions in a direction in which the polishing units103C and 103D are arranged (referred to as a fifth transport positionTP5, a sixth transport position TP6, and a seventh transport positionTP7 in order from the side of the load/unload section).

The substrate is transported to the polishing units 103A and 103B by thefirst linear transporter 106. As described above, the top ring 131A ofthe first polishing unit 103A moves between a polishing position and thesecond transport position TP2 by a swing motion of a top ring head (notshown). Therefore, transfer of the substrate to the top ring 131A isperformed at the second transport position TP2. Similarly, the top ring131B of the second polishing unit 103B moves between a polishingposition and the third transport position TP3, and transfer of thesubstrate to the top ring 131B is performed at the third transportposition TP3. The top ring 131C of the third polishing unit 103C movesbetween a polishing position and the sixth transport position TP6, andtransfer of the substrate to the top ring 131C is performed at the sixthtransport position TP6. The top ring 131D of the fourth polishing unit103 moves between a polishing position and the seventh transportposition TP7, and transfer of the substrate to the top ring 131D isperformed at the seventh transport position TP7.

A lifter 111 for receiving the substrate from the transport robot 122 isdisposed at the first transport position TP1. The substrate istransferred from the transport robot 122 to the first linear transporter106 via the lifter 111. A shutter (not shown) is disposed between thelifter 111 and the transport robot 122 on the partition wall 101 a. Whenthe substrate is transported, the shutter is opened, and the substrateis transferred from the transport robot 122 to the lifter 111. A swingtransporter (not shown) is disposed among the first linear transporter106, the second linear transporter 107, and the cleaning section 104.This swing transporter has a hand that can move between the fourthtransport position TP4 and the fifth transport position TP5 andtransfers the substrate from the first linear transporter 106 to thesecond linear transporter 107. The substrate is transported to the thirdpolishing unit 103C and/or the fourth polishing unit 103D by the secondlinear transporter 107. The substrate polished by the polishing section103 is transported to the cleaning section 104 via the swingtransporter.

FIG. 2A is a plan view showing the cleaning section 104, and FIG. 2B isa side view showing the cleaning section 104. As shown in FIGS. 2A and2B, the cleaning section 104 is partitioned into a first cleaningchamber 190, a first transport chamber 191, a second cleaning chamber192, a second transport chamber 193, and a drying chamber 194. In thefirst cleaning chamber 190, an upper primary substrate cleaningapparatus 201A and a lower primary substrate cleaning apparatus 201Barranged in a longitudinal direction are disposed. The upper primarysubstrate cleaning apparatus 201A is disposed above the lower primarysubstrate cleaning apparatus 201B. Similarly, in the second cleaningchamber 192, an upper secondary substrate cleaning apparatus 202A and alower secondary substrate cleaning apparatus 202B arranged in alongitudinal direction are disposed. The upper secondary substratecleaning device 202A is disposed above the lower secondary substratecleaning device 202B. The substrate cleaning apparatuses 201A, 201B,202A, and 202B are cleaning machines configured to clean a substrateusing a cleaning liquid. The substrate cleaning apparatuses 201A, 201B,202A, and 202B are arranged in the vertical direction, and thereforehave an advantage that a footprint area is small.

A temporary placement stand 203 for a substrate is disposed between theupper secondary substrate cleaning apparatus 202A and the lowersecondary substrate cleaning apparatus 202B. In the drying chamber 194,an upper drying module 205A and a lower drying module 205B arranged in alongitudinal direction are disposed. The upper drying module 205A andthe lower drying module 205B are isolated from each other. Filter fanunits 207 and 207 for supplying clean air into the drying modules 205Aand 205B are disposed above the upper drying module 205A and the lowerdrying module 205B, respectively. The upper primary substrate cleaningapparatus 201A, the lower primary substrate cleaning apparatus 201B, theupper secondary substrate cleaning apparatus 202A, the lower secondarysubstrate cleaning apparatus 202B, the temporary placement stand 203,the upper drying module 205A, and the lower drying module 205B are fixedto a frame (not shown) via bolts and the like.

In the first transport chamber 191, a first transport robot 209 that canvertically move is disposed. In the second transport chamber 193, asecond transport robot 210 that can vertically move is disposed. Thefirst transport robot 209 and the second transport robot 210 aresupported by support shafts 211 and 212 extending in a longitudinaldirection so as to be movable, respectively. The first transport robot209 and the second transport robot 210 each have a driving mechanismsuch as a motor therein and can vertically move along the support shafts211 and 212, respectively. Like the transport robot 122, the firsttransport robot 209 has two-stage hands composed of upper and lowerhands. As indicated by the dotted line in FIG. 2A, the first transportrobot 209 is disposed at a position where the lower hand thereof canaccess a temporary placement stand 180. When the lower hand of the firsttransport robot 209 accesses the temporary placement stand 180, ashutter (not shown) disposed in the partition wall 101 b opens.

The first transport robot 209 operates so as to transport the substrateW among the temporary placement stand 180, the upper primary substratecleaning apparatus 201A, the lower primary substrate cleaning apparatus201B, the temporary placement stand 203, the upper secondary substratecleaning apparatus 202A, and the lower secondary substrate cleaningapparatus 202B. When a substrate before cleaning (substrate to which aslurry is attached) is transported, the first transport robot 209 usesthe lower hand. When a substrate after cleaning is transported, thefirst transport robot 209 uses the upper hand. The second transportrobot 210 operates so as to transport the substrate W among the uppersecondary substrate cleaning apparatus 202A, the lower secondarysubstrate cleaning apparatus 202B, the temporary placement stand 203,the upper drying module 205A, and the lower drying module 205B. Thesecond transport robot 210 transports only a cleaned substrate, andtherefore has only one hand. The transport robot 122 shown in FIG. 1takes out a substrate from the upper drying module 205A or the lowerdrying module 205B using the upper hand thereof and returns thesubstrate to a wafer cassette. When the upper hand of the transportrobot 122 accesses the drying modules 205A and 205B, a shutter (notshown) disposed in the partition wall 101 a opens.

The cleaning section 104 includes two primary substrate cleaningapparatuses and two secondary substrate cleaning apparatuses, andtherefore can configure a plurality of cleaning lines configured toclean a plurality of substrates in parallel.

In the present embodiment, the primary substrate cleaning apparatuses201A and 201B and the secondary substrate cleaning apparatuses 202A and202B are roll sponge type cleaning machines. Incidentally, here, theroll sponge means an elongated sponge, and a rotation shaft (not shown)made of a hard material is disposed in a longitudinal direction.

The upper primary substrate cleaning apparatus 201A, the lower primarysubstrate cleaning apparatus 201B, the upper secondary substratecleaning apparatus 202A, and the lower secondary substrate cleaningapparatus 202B may be the same type of substrate cleaning apparatuses ordifferent types of substrate cleaning apparatuses. For example, theprimary substrate cleaning apparatuses 201A and 201B may be roll typesubstrate cleaning apparatuses (refer to FIG. 7) for scrub cleaningupper and lower surfaces of a substrate with a pair of roll sponges, andthe secondary substrate cleaning apparatuses 202A and 202B may be penciltype substrate cleaning apparatuses (refer to FIG. 8).

(Substrate Cleaning Apparatus)

Next, the detailed constitution of a roll type or pencil type substratecleaning apparatus used as the substrate cleaning apparatuses 201A,201B, 202A, and 202B will be described. These substrate cleaningapparatuses each include a substrate holding and rotating mechanism 1shown in FIGS. 3 to 6 commonly. By disposing a roll type cleaningmechanism 2A (see FIG. 7) or a pencil type cleaning mechanism 2B (seeFIG. 8) above the substrate holding and rotating mechanism 1, each ofthe substrate cleaning apparatuses 201A, 201B, 202A, 202B is configured.

(Substrate Holding and Rotating Mechanism)

First, the substrate holding and rotating mechanism 1 will be described.As shown in FIG. 3, a cleaning member driving mechanism 30 for drivingthe cleaning mechanism 2A or the cleaning mechanism 2B is disposed inthe central portion of the substrate holding and rotating mechanism 1. Afirst moving mechanism 10 and a second moving mechanism 20 are disposedon both sides sandwiching the cleaning member driving mechanism 30. Thefirst moving mechanism 10 moves a first spindle group G1, and the secondmoving mechanism 20 moves a second spindle group G2. The first spindlegroup G1 includes a first driving spindle 50A and an idler spindle 50B,and the second spindle group G2 includes a plurality of second drivingspindles 50C.

As shown in FIGS. 7 and 8, the first driving spindle 50A includes adriving roller 52 (first driving roller), the idler spindle 50B includesa driven roller 54, and each of the second driving spindles 50C includesa driving roller 52 (second driving roller).

The substrate holding and rotating mechanism 1 rotates the substrate Wby a rotational force of the driving roller 52 while holding thesubstrate W by holding grooves 52 a and 54 a for the driving rollers 52and the driven roller 54.

The cleaning member driving mechanism 30 includes a cylinder 32 (notshown in FIG. 4) disposed inside a case 31 shown in FIG. 4 and arod-shaped support member 33 driven by the cylinder 32. The supportmember 33 protrudes upward from the cylinder 32 and can vertically moveby driving of the cylinder 32.

As shown in FIG. 3, an attachment portion 34 to which a cleaningmechanism described below is attached is disposed at an upper end of thesupport member 33. Meanwhile, a pair of linear slide rails 36 arrangedin parallel to each other with the case 31 sandwiched therebetween isdisposed on both sides of the case 31. To both ends of the pair of sliderails 36, the first moving mechanism 10 and the second moving mechanism20 are attached so as to be slidable.

(First Moving Mechanism)

Here, the constitution of the first moving mechanism 10 will bedescribed. As shown in FIGS. 3 and 4, a slider 12 having a substantiallyU-shaped cross section is engaged with each of the slide rails 36. Theslider 12 slides with respect to each of the slide rails 36 in adirection in which the slide rails 36 extend. A connecting member 13formed in a substantially rectangular flat plate shape is attached to alower surface of each of the sliders 12. An opening 13 a verticallypenetrating the connecting member 13 is disposed in the central portionof the connecting member 13, and a bearing 14 is fitted to an innerperiphery of the opening 13 a. A substantially columnar shaft member 15is attached to an inner ring 14 a of the bearing 14. The shaft member 15is rotatably held in the opening 13 a by the bearing 14 with respect tothe connecting member 13. A cover 16 covering an upper surface of theshaft member 15 disposed in the opening 13 a is attached to the top ofthe opening 13 a.

A base member 17 formed in a substantially rectangular flat plate shapeis disposed on a lower surface side of the connecting member 13. Theouter shape of the base member 17 is larger than that of the connectingmember 13, and the central portion of the upper surface thereof is fixedto a lower end surface of the shaft member 15 via bolts. As a result,the base member 17 rotates integrally with the shaft member 15 aroundthe shaft member 15 in a horizontal plane as shown in FIG. 6.

As shown in FIG. 4, a substantially rectangular recess 17 a for housinga lower portion of the connecting member 13 is formed on an uppersurface of the base member 17. A clearance D (refer to FIG. 6) of asmall size is disposed between an inner peripheral surface of the recess17 a and an outer peripheral surface of the connecting member 13.Therefore, the base member 17 can rotate with respect to the connectingmember 13 within a range where the connecting member 13 and the basemember 17 are not in contact with each other with the clearance D. Notethat the width of the clearance D is about 2 mm in the presentembodiment.

As shown in FIG. 5, a guide member 18 having a substantially L shape andhaving one end thereof facing downward is attached outside the basemember 17 (outside the base member 17 in an extending direction of theslide rails 36). A plate-shaped locking member 19 having an upper endfixed to a partition member 3 described below is disposed inside theguide member 18. A cylinder 22 is attached to the inside of the lockingmember 19, and a tip of a rod 24 driven to advance and retreat by thecylinder 22 is connected to the inside of the guide member 18 via afloating joint 21.

Although not shown in detail, the floating joint 21 is constituted by apair of connectors attached to the rod 24 side and the guide member 18side. A spherical projection 21 a in one of the connectors is rotatablyengaged with the inside of a spherical recess 21 b in the otherconnector. As a result, the guide member 18 is connected to the rod 24so as to be swingable (rotatable) in substantially all the directions.Therefore, the base member 17 and the connecting member 13 can beintegrally reciprocated along the slide rails 36 by driving of thecylinder 22, and the base member 17 and the guide member 18 can freelyrotate in a horizontal plane independently of the locking member 19 andthe cylinder 22.

As shown in FIG. 5, a protruding stopper member 23 which has a tip incontact with an outer surface of the locking member 19 and regulatesmovement of the base member 17 and the connecting member 13 at apredetermined position is attached to an inner surface of the guidemember 18. Note that reference numeral 37 represents a regulatorattached to the cylinder 22. As described above, the first movingmechanism 10 includes a reciprocating mechanism for integrallyreciprocating the base member 17 and the connecting member 13 in alinear direction along the slide rails 36 and a rotating mechanism forrotatably disposing the base member 17 with respect to the connectingmember 13 around the shaft member 15 in a horizontal plane.

That is, the first moving mechanism 10 holds the first spindle group G1so as to be slidable along the slide rails 36 and rotationally movablearound the shaft member 15.

As shown in FIG. 4, each of the spindles 50A and 50B includes acylindrical main body 51 and a shaft 26 inserted into the main body 51.Incidentally, although not shown, the constitution of the second drivingspindle C is similar to that of the first driving spindle 50A.

As shown in FIG. 3, an attachment portion 51 a for attaching the drivingroller 52 or the driven roller 54 (refer to FIG. 7) is disposed at anupper end of the main body 51 in each of the spindles 50A and 50B. Anupper end 26 a of the shaft 26 protruding from the attachment portion 51a is connected to the driving roller 52 or the driven roller 54, and theshaft 26 and the driving roller 52 or the driven roller 54 therebyrotate integrally. Note that FIG. 3 shows a state in which the drivingroller 52 and the driven roller 54 have been removed from the attachmentportion 51 a.

As shown in FIGS. 4 and 6, both sides of the base member 17 protrude toboth outer sides of each of the slide rails 36 (both outer sidesorthogonal to the extending direction of the slide rails 36), and thefirst driving spindle 50A and the idler spindle 50B stand upright on anupper surface of the protruding portion. As shown in FIG. 4, the shaft26 rotatably disposed in the main body 51 of each of the spindles 50Aand 50B penetrates the base member 17 and protrudes to a lower surfaceside thereof. A motor 28 is disposed below the base member 17, and atransmission belt 29 is stretched between a rotation shaft 28 a of themotor 28 and the shaft 26 in the first driving spindle 50A. The motor 28inputs a driving force to the shaft 26 of the first driving spindle 50Avia the transmission belt 29 and rotates the shaft 26 and the drivingroller 52 integrally.

As shown in FIG. 7, the holding grooves 52 a and 54 a in contact with anouter periphery of the substrate W are formed on outer peripheralsurfaces of the driving roller 52 and the driven roller 54. By rotationof the driving rollers 52 in a state where a peripheral portion of thesubstrate W is held in the holding groove 52 a, the substrate W isrotated. In addition, by rotation of the substrate W in a state wherethe substrate W is held in the holding groove 54 a in the driven roller54, the shaft 26 of the idler spindle 50 is driven to rotate togetherwith the driven roller 54.

As shown in FIG. 4, a rotation detector 53 including a pair of dogs 53 aand a sensor 53 b configured to detect rotation of the dogs 53 a isdisposed at a lower end of the shaft 26 of the idler spindle 50B. Thepair of dogs 53 a extends from the center axis of the shaft 26 of theidler spindle 50B toward an outside thereof. As the sensor 53 b, forexample, an optical sensor including a light projecting portion and alight receiving portion can be used.

In the rotation detector 53, an output signal of the sensor 53 b changesdepending on whether the dogs 53 a are positioned between the lightprojecting portion and the light receiving portion of the sensor 53 b,and the rotational speed of the dogs 53 a, that is, the rotational speedof the driven roller 54 can be detected, for example, from a timeinterval at which the output signal changes. The rotational speed of thesubstrate W is proportional to the rotational speed of the driven roller54, and therefore the rotational speed of the substrate W can becalculated from the rotational speed of the driven roller 54.

As described above, the rotation detector 53 indirectly detects therotational speed of the substrate W by detecting the rotational speed ofthe driven roller 54.

(Second Moving Mechanism)

The second moving mechanism 20 includes a single base member 25corresponding to one obtained by integrally constituting the members 13and 17 in place of the base member 17 and the connecting member 13included in the first moving mechanism 10. In the second movingmechanism 20, although not shown, the shafts 26 of the two seconddriving spindles 50C rotate synchronously by a motor. The constitutionsof the other parts of the second moving mechanism 20 are common to thoseof the first moving mechanism 10. Therefore, in the drawings anddescription of the second moving mechanism 20, the same referencenumeral is given to components common to the first moving mechanism, anda detailed description thereof will be omitted.

As shown in FIG. 3, in the second moving mechanism 20, a lower surfaceof the slider 12 is directly attached to an upper surface of the basemember 25 without disposing members corresponding to the connectingmember 13 and the shaft member 15, and only a reciprocating mechanismfor reciprocating the base member 25 in a linear direction along theslide rails 36 is included.

That is, the second moving mechanism 20 holds the second spindle groupG2 so as to be slidable in a linear direction along the slide rails 36and not to be rotationally movable.

(Roll Type Cleaning Mechanism)

Next, the roll type cleaning mechanism 2A attached to the top of thesubstrate holding and rotating mechanism 1 will be described. Thecleaning mechanism 2A shown in FIG. 7 includes a roll cleaning member 60configured to clean the substrate W, an upper nozzle 71 for supplying acleaning liquid toward an upper surface of the substrate W, and a lowernozzle 72 for supplying a cleaning liquid toward a lower surface of thesubstrate W.

The roll cleaning member 60 includes an upper cleaning member 61configured to clean an upper surface of the substrate W and a lowercleaning member 62 configured to clean a lower surface of the substrateW. The cleaning members 61 and 62 include columnar roll sponges 63 and64 slidably in contact with an upper surface or a lower surface of thesubstrate W and roll sponge attachment members 65 and 66 to which theroll sponges 63 and 64 are rotatably attached, respectively. Examples ofa material of the roll sponges 63 and 64 include a porous PVA sponge andfoamed polyurethane. The cleaning members 61 and 62 are disposed suchthat longitudinal directions thereof extend between the spindle groupsG1 and G2.

Each of the roll sponges 63 and 64 is formed into a length equal to orlarger than the diameter of the substrate W so as to be slidably incontact with the entire upper and lower surfaces of the substrate W. Inaddition, the upper cleaning member 61 is attached to a drivingmechanism (not shown) for vertically moving and rotating the roll sponge63. Meanwhile, although not shown in detail, the lower cleaning member62 is attached to the attachment portion 34 of the support member 33.

The upper nozzle 71 and the lower nozzle 72 are connected to a cleaningliquid supply source (not shown) and inject a cleaning liquid toward anupper surface or a lower surface of the substrate W. Examples of thecleaning liquid include ultrapure water, ammonia water, and hydrofluoricacid.

As shown in FIG. 7, the roll sponge 63 rotates in a direction of pushingthe substrate W toward the second spindle group G2 at a contact portionwith the substrate W. Similarly, the roll sponge 64 rotates in adirection of pushing the substrate W toward the second spindle group G2at a contact portion with the substrate W. As a result, the substrate Wreceives a pushing force (refer to arrow F) toward the second spindlegroup G2 from the roll cleaning member 60. Hereinafter, a direction inwhich the substrate W receives a force from the cleaning mechanism 2A inthis way will be simply referred to as a pressing direction F.

(Pencil Type Cleaning Mechanism)

Next, the pencil type cleaning mechanism 2B will be described. Thecleaning mechanism 2B shown in FIG. 8 includes a rotation shaft 67, aswing arm 68, and a pencil type cleaning member 69. The swing arm 68 isrotated around the rotation shaft 67. The cleaning member 69 is attachedto a lower surface of the swing arm 68 at a tip thereof. The pencil typecleaning member 69 in the present embodiment is formed in a cylindricalshape extending in the vertical direction. Examples of a material of thecleaning member 69 include foamed polyurethane and PVA.

When the swing arm 68 rotates around the rotation shaft 67, the pencilcleaning member 69 attached to the tip of the swing arm 68 moves on thesubstrate W in an arc-shaped locus. The tip of the swing arm 68 extendsto the center of the substrate W. Therefore, the movement locus of thepencil cleaning member 69 passes through the center of the substrate W.The pencil cleaning member 69 is moved to an outer periphery of thesubstrate W. By movement of the pencil cleaning member 69 in the locusas described above while the substrate W rotates, the entire uppersurface of the substrate W is cleaned by the pencil cleaning member 69.

Here, a swinging direction of the swing arm 68 while the pencil cleaningmember 69 is in contact with the substrate W is directed from the firstspindle group G1 toward the second spindle group G2 as indicated by anarrow R in FIG. 8. By swinging of the swing arm 68 in this way, thesubstrate W receives a pushing force (refer to arrow F) toward thesecond spindle group G2 from the pencil cleaning member 69. Note thatthe direction of the arrow F is the same direction as the direction ofthe pushing force by the roll cleaning member 60 shown in FIG. 7. Thatis, the pressing direction F in the pencil type cleaning mechanism 2B issimilar to the pressing direction F in the roll type cleaning mechanism2A.

The whole of the substrate cleaning apparatus configured as describedabove is housed in a box-shaped casing. As shown in FIGS. 4 and 5, uppersurfaces of the slide rails 36 and an upper surface of the case 31 arefixed to a lower surface side of a plate-shaped partition member 3disposed in the casing. The inside of the casing is partitioned into alower space and an upper space by the partition member 3. The substrateholding and rotating mechanism 1 is housed in the lower space, and thecleaning mechanism 2A or 2B is housed in the upper space. The partitionmember 3 prevents a cleaning liquid and the like configured to clean asubstrate with the cleaning mechanism 2A or 2B from reaching thesubstrate holding and rotating mechanism 1 in the lower space. Note thatthe spindles 50A to 50C and the support member 33 protrude upward fromthe partition member 3 through an opening 3 a or the like formed in thepartition member 3.

Next, an action of the substrate cleaning apparatus configured asdescribed above will be described with reference to FIGS. 9A to 9D andFIG. 10.

FIGS. 9A to 9D are schematic views of the substrate cleaning apparatusas viewed from above. A straight line L shown in FIGS. 9A to 9Dindicates a position where the pair of slide rails 36 extend.Hereinafter, the direction in which the slide rails 36 extend will besimply referred to as a slide direction L FIG. 10 shows a flow ofcleaning a substrate.

When the substrate W is held, as shown in FIG. 9A, the first spindlegroup G1 and the second spindle group G2 disposed on both sidessandwiching the substrate W in the slide direction L are moved by thefirst moving mechanism 10 and the second moving mechanism 20 toward thesubstrate W. At this time, the second spindle group G2 comes intocontact with the substrate W earlier than the first spindle group G1.Both the first spindle group G1 and the second spindle group G2 comeinto contact with a peripheral portion of the substrate W, and thesubstrate W is thereby held (S101 in FIG. 10).

By the way, when the substrate W is held in this way, it is alsoconsidered that the driving roller 52 of the first driving spindle 50Aand the driven roller 54 of the idler spindle 50B are not in contactwith the peripheral portion of the substrate W under a pressure equal toeach other. However, in the present embodiment, as shown in FIG. 9B, oneof the driving roller 52 and the driven roller 54 is into contact withthe peripheral portion of the substrate W, the base member 17 therebyrotates around the shaft member 15, and the other comes into contactwith the peripheral portion of the substrate W. By this operation,imbalance of a holding force configured to hold the substrate W by thedriving roller 52 and the driven roller 54 is corrected, and the rollersare brought into contact with the peripheral portion of the substrate Wunder a pressure equal to each other.

Subsequently, the motor 28 is driven to rotate the driving roller 52 ofeach of the driving spindles 50A and SOC. As shown in FIG. 9C, thesubstrate W is rotated (S102 in FIG. 10). At this time, along with therotation of the substrate W, the driven roller 54 is also driven torotate. When the driven roller 54 rotates, the dogs 53 a attached to theshaft 26 of the idler spindle 50B also rotate, and an ON/OFF signaloutput from the sensor 53 b is switched at an interval corresponding tothe rotational speed of the dogs 53 a. Therefore, from the time intervalat which the ON/OFF signal is switched, the rotational speed of thedriven roller 54 can be detected. Furthermore, the driven roller 54 isdriven by the rotation of the substrate W, and therefore the rotationalspeed of the substrate W can be indirectly calculated.

When the substrate W starts to rotate, the roll cleaning member 60 orthe pencil cleaning member 69 is pressed against the substrate W whilethe nozzles 71 and 72 inject a cleaning liquid toward the substrate W,and the substrate W is cleaned (S103 in FIG. 10). At this time, as shownin FIG. 9D, a pushing force in the pressing direction F toward thesecond spindle group G2, received from the roll cleaning member 60 orthe pencil cleaning member 69, acts on the substrate W. Each of theplurality of driving rollers 52 included in the second spindle group G2applies a rotational force to the substrate W. Therefore, the rotationalforce can be reliably applied to the substrate W, for example, ascompared with a case where the idler spindle 50B is included in thesecond spindle group G2.

After completion of cleaning, the injection of the cleaning liquid isstopped, the roll cleaning member 60 or the pencil cleaning member 69 isseparated from the substrate W (S104 in FIG. 10), and the rotation ofthe substrate W is stopped (S105 in FIG. 10). Thereafter, when asubstrate gripping mechanism (for example, a hand mechanism) (not shown)receives the substrate W, the substrate W is removed from the firstspindle group G1 and the second spindle group G2 (S106 in FIG. 10).

Furthermore, in the present embodiment, the driven roller 54 rotated bythe substrate W is positioned on the opposite side to the pressingdirection F. This makes it possible to effectively utilize a pressingforce of the cleaning members 60 and 69 as a force for pressing thesubstrate W against the driving roller 52, for example, as compared witha case where the driven roller 54 is positioned in a direction in whichthe substrate W receives a force from the cleaning members 60 and 69.Therefore, the substrate W can be more reliably rotated by the drivingroller 52.

In addition, the number of rollers in contact with the substrate W isreduced, and occurrence of contamination of the substrate W by dirtattached to these rollers can be suppressed, for example, as comparedwith a case where the driven roller 54 is added to the constitution ofJapanese Patent No. 4937807.

Furthermore, even if the pressing force of the driven roller 54 againstthe substrate W is equal to the pressing force of the driving roller 52against the substrate W, a balance of the forces applied to thesubstrate W is not deteriorated as compared with the constitution ofJapanese Patent No. 4937807. Therefore, it is possible to suppress slipoccurring between the driven roller 54 and the substrate W by pressingthe driven roller 54 against the substrate W with a strong force whilesuppressing deformation of the substrate W or the like.

In addition, the first moving mechanism 10 holds the first spindle groupG so as to be slidable and rotationally movable, and the second movingmechanism 20 holds the second spindle group G2 so as to be slidable andnot to be rotationally movable. With this constitution, when thesubstrate W is held between the first spindle group G1 and the secondspindle group G2, the first spindle group G1 rotationally moves, and abalance of holding forces of the substrate W by the spindles 50A to 50Ccan be thereby uniform.

Incidentally, in another embodiment, even after the motor 28 is drivento rotate the driving rollers 52 of the driving spindles 50A and 50C torotate the substrate W, it may be detected whether the rollers are incontact with a peripheral portion of the substrate W with a pressingforce equal to each other, for example, using a load cell (not shown)disposed in a spindle for supporting the rollers. Based on the detectionresult, a position adjustment mechanism (not shown) disposed on eitherthe first moving mechanism 10 or the second moving mechanism 20 maycorrect a relative distance between the first spindle group G1 and thesecond spindle group G2, and subsequently cleaning may be performed.Alternatively, the relative distance between the first spindle group G1and the second spindle group G2 may be corrected by considering thecalculation result of the rotational speed of the substrate W and thepressing force detected using the load cell (not shown), andsubsequently cleaning may be performed. As a result, it is possible tomore reliably suppress slip occurring between the driven roller and thesubstrate by pressing the driven roller against the substrate with arelatively strong force while suppressing deformation of the substrateor the like, and to stabilize the quality of cleaning of the substratewhile accurately measuring the rotational speed of the substrate.

As described above, according to the substrate cleaning apparatus of thepresent embodiment, the rotation detector 53 detects the rotationalspeed of the driven roller 54, and it is thereby possible to stabilizethe quality of cleaning of the substrate W while accurately measuringthe rotational speed of the substrate W.

Furthermore, according to a substrate processing apparatus 200 of thepresent embodiment, when the substrate W polished by the polishingsection 103 is cleaned by the substrate cleaning apparatuses 201A, 2018,202A, and 202B, it is possible to suppress, for example, attachment ofdirt of the driving roller 52 or the driven roller 54 to the substrate Wagain and to stabilize the quality of the processed substrate W whileaccurately measuring the rotational speed of the substrate W.

Note that the technical scope of the present invention is not limited tothe above embodiment, and various modifications can be made withoutdeparting from the gist of the present invention.

For example, in the above embodiment, each of the first spindle group Gand the second spindle group G2 has two spindles, but the number ofspindles included in each of the spindle groups G1 and G2 may beappropriately changed.

In addition, in the above embodiment, the rotational speed of the drivenroller 54 is detected by the dogs 53 a and the sensor 53 b, but therotational speed of the driven roller 54 may be detected by another typeof rotation detector. For example, the rotational speed of the drivenroller 54 may be detected by measuring the peripheral speed of the shaft26 of the idler spindle 50B with a non-contact type speedometer or thelike. In this case, the non-contact type speedometer corresponds to therotation detector.

The moment of inertia when the driven roller 54 rotates may be smallerthan the moment of inertia when the driving roller 52 rotates. In thiscase, along with the rotation of the substrate W, the driven roller 54is more likely to rotate, and slip between the driven roller 54 and thesubstrate W hardly occurs. This makes it possible to detect therotational speed of the substrate W more accurately.

Incidentally, as a method of reducing the moment of inertia when thedriven roller 54 rotates, it is considered that the outer diameter ofthe shaft 26 in the idler spindle 50B is made smaller than the outerdiameter of the shaft 26 in another spindle 50A or 50C. Alternatively,as a material of the shaft 26 of the idler spindle 50B, it is alsoconsidered to adopt a material having a lower density than the materialof another shaft 26. According to these forms, it is possible to reducethe moment of inertia when the driven roller 54 rotates while thedriving roller 52 and the driven roller 54 which are consumables areformed of the same kind of parts. In other words, by making parts of thedriving roller 52 and the driven roller 54 common, cost can be reduced,and maintainability can be improved.

In the above embodiment, the substrate holding and rotating mechanism 1in which the spindles 50A to 50C extend in the vertical direction andthe substrate W is horizontally held has been described. However, asubstrate holding and rotating mechanism in which the substrate W isvertically held, that is, a so-called upright type substrate holding androtating mechanism may be adopted. In this case, it is possible to adoptsuch a form that the whole of the substrate holding and rotatingmechanism 1 described in the above embodiment is tilted by 90°. In thiscase, when the substrate is pressed against the spindle, if therotational speed is detected for a spindle positioned downward as viewedfrom the center of the substrate, an influence of a load of thesubstrate itself is also estimated. Therefore, it is also possible todetect the rotational speed for a spindle positioned upward as viewedfrom the center of the substrate.

The substrate processing apparatus 200 of the above embodiment includesboth the roll type substrate cleaning apparatus and the pencil typesubstrate cleaning apparatus. However, the substrate processingapparatus 200 including either one of the substrate cleaning apparatusesmay be adopted. The number and arrangement of the substrate cleaningapparatuses included in the substrate processing apparatus 200 can beappropriately changed. Alternatively, in place of the above polishingapparatus, another semiconductor processing apparatus such as a platingapparatus or a grinding apparatus may be used, and the substratecleaning apparatus may be disposed at a subsequent stage of thesemiconductor processing apparatus.

Besides, it is possible to appropriately replace the constituentelements in the above embodiment with well-known constituent elements,and the above embodiment and modification may be appropriately combinedwithout departing from the gist of the present invention.

1-7. (canceled)
 8. A substrate cleaning apparatus comprising: a drivingroller configured to rotate a substrate; a driven roller rotated bycontacting with the substrate which rotates; a cleaning mechanismconfigured to clean the substrate which rotates; and a rotation detectorconfigured to detect a rotational speed of the driven roller, wherein:the driven roller is positioned on an opposite side to a direction inwhich the substrate receives a force from the cleaning mechanism; andthe rotation detector comprises a pair of dogs rotatable with the drivenroller and a sensor comprises a light projecting portion and a lightreceiving portion, and the rotation detector is configured to detect arotational speed of the pair of dogs based on an output signal of thesensor that changes depending on whether or not the pair of dogs arepositioned between the light projecting portion and the light receivingportion.
 9. The substrate cleaning apparatus according to claim 8,further comprising a first spindle group comprising a first drivingspindle having a first driving roller and an idler spindle having thedriven roller; and a second spindle group comprising a plurality ofsecond driving spindles each having a second driving roller; wherein:the driving roller comprises the first driving roller and the seconddriving roller; the cleaning mechanism comprises a roll cleaning memberconfigured to be in contact with the substrate which rotates; and theroll cleaning member is configured to rotate in a direction of pushingthe substrate toward the second spindle group at a contact portion withthe substrate.
 10. The substrate cleaning apparatus according to claim8, further comprising: a first spindle group comprising a first drivingspindle having a first driving roller and an idler spindle having thedriven roller; and a second spindle group comprising a plurality ofsecond driving spindles each having a second driving roller; wherein:the driving roller comprises the first driving roller and the seconddriving roller; the cleaning mechanism comprises a pencil cleaningmember configured to be in contact with the substrate which rotates anda swing arm to which the pencil cleaning member is attached so as toswing in a predetermined locus connecting a center and an outerperiphery of the substrate; and the swing arm swings in a direction fromthe first spindle group toward the second spindle group.
 11. Thesubstrate cleaning apparatus according to claim 9, further comprising: afirst spindle group comprising a first driving spindle having a firstdriving roller and an idler spindle having the driven roller; and asecond spindle group comprising a plurality of second driving spindleseach having a second driving roller; wherein: the driving rollercomprises the first driving roller and the second driving roller; thecleaning mechanism comprises a pencil cleaning member configured to bein contact with the substrate which rotates and a swing arm to which thepencil cleaning member is attached so as to swing in a predeterminedlocus connecting a center and an outer periphery of the substrate; andthe swing arm swings in a direction from the first spindle group towardthe second spindle group.
 12. The substrate cleaning apparatus accordingto claim 8, wherein the rotation detector configured to calculate therotational speed of the substrate from the rotational speed of the pairof dogs.